Effects of Dzyaloshinskii-Moriya interaction on the spin transfer magnetization switching in magnetic tunnel junctions

Magnetic tunnel junction (MTJ) are at the center of the magnetic random access memories (MRAM) technology. Nowadays, the research and development efforts are focusing on perpendicularly magnetized layers in the MTJ, taking advantage of the anisotropy provided by spin-orbit coupling at the interfaces with heavy metals such as Pt or Ta [1]. Recently, interfaces between ferromagnetic and heavy metals are also studied in a more fundamental context, because an antisymmetric interaction might appear at the interface, namely an interfacial Dzyaloshinskii-Moriya interaction (DMI) [2]. We will present a micromagnetic study of the reversal of the free layer magnetization direction by spin transfer torque under different amplitudes of the DMI. In particular, we will evaluate the energy barrier E b or equivalently the thermal stability Δ=E b /(300k B ) and the minimal current density necessary for switching J c0 as a function of the DMI amplitude.